virtio — archive

[Michael S. Tsirkin]

--- content.tex 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/content.tex b/content.tex index 0cca0e0..5f5fdfb 100644 --- a/content.tex +++ b/content.tex @@ -279,7 +279,11 @@ Descriptor Table & Available Ring (ldots paddingldots) & Used Ring \ end{tabular} The bus-specific Queue Size field controls the total number of bytes -required for the virtqueue according to the following formula: +required for the virtqueue. +When using the legacy interface, the transitional +driver MUST retrieve the Queue Size field from the device +and MUST allocate the total number of bytes for the virtuqueue +according to the following formula: egin{lstlisting} #define ALIGN(x) (((x) + PAGE_SIZE) & ~PAGE_SIZE) @@ -291,7 +295,9 @@ static inline unsigned vring_size(unsigned int qsz) end{lstlisting} This wastes some space with padding. -The legacy virtqueue layout structure therefore looks like this: +When using the legacy interface, both transitional +devices and drivers MUST use the following virtqueue layout +structure to locate elements of the virtqueue: egin{lstlisting} struct vring { -- MST